Interrupter having positive stop means for contact elements



Nov. 1, 1966 J. H. ANSON 3,283,107

INTERRUPTER HAVING POSITIVE STOP MEANS FOR CONTACT ELEMENTS Filed July20, 1964 5 $heetsSheet 1 ii .1. 7 14 6'1 26 J0 9a L I 16 LfiZ/QQJZ forJames 77. 0223012 f] Nov. 1, 1966 J. H. ANSON 3,283,107

INTERRUPTER HAVING POSITIVE STOP MEANS FOR CONTACT ELEMENTS Filed July20, 1964 s Sheets-Shet 2 \L {I 1 I Li/ t? Nov. 1, 1966 J. H. ANSON3,283,107

vINTERRUP'IER HAVING POSITIVE STOP MEANS FOR CONTACT ELEMENTS Filed July20, 1964 5 Sheets-Sheet 5 James 7% @223022 f MManv W MI 9L (My;

United States Patent 3,283,107 INTERRUPTER HAVING POSITIVE STOP MEANSFOR CONTACT ELEMENTS James H. Anson, Auburn, 11]., assignor to SangamoElectric Company, Springfield, 11]., a corporation of Dela- Ware FiledJuly 20, 1964, Ser. No. 383,600 6 Claims. (Cl. 200-166) This inventionrelates to circuit interrupters for use in telephone circuitry andanalogous purposes.

It is known to provide cam actuated switch means for brieflyinterrupting, at short and uniform time intervals, the circuit of alight connected to a telephone circuit to produce a wink signal. Thewink signal means is associated with supplementary telephone circuitrywell known in the art and which requires no detail description. TheHaydon patent, No. 3,106,620, discloses a circuit interrupter comprisingcam actuated means of the character stated for producing a wink signaland cam actuated means for controlling associated supplementarycircuitry.

The interrupter of my present invention is broadly similar to the switchmeans of the Haydon patent, but is directed to certain improvements inthe means for controlling the supplementary circuitry. Such meanscomprises cam actuated movable contact elements cooperating with opposedcontact elements, which may be referred to as the stationary contactelements. It is important that the contact elements have a wiping actionduring closing thereof, assuring that they are maintained in a cleancondition at all times. Also, it is of importance that the stationarycontact elements be accurately adjusted relative to the movable elementsand maintained in such adjustment while also having positively limitedmovement incident to opening of the movable contact elements, effectivefor assuring breaking of any weld which may occur between the movableand the stationary contact elements. My invention is directed to meanswhereby attainment of the stated objectives is assured. Further objectsand advantages of my invention will appear from the detail description.

In the drawings:

FIGURE 1 is a top plan view of a telephone interrupter embodying myinvention;

FIGURE 2 is a sectional view taken substantially on line 22 of FIGURE 1,with certain parts broken away;

FIGURE 3 is an end view of the interrupter of FIG- URE 1; with certainparts broken away and one of the gears partly broken away and shown insection;

FIGURE 4 is an underneath plan view of the interrupter of FIGURE 1;

FIGURE 5 is a fragmentary sectional view taken substantially on line 55of FIGURE 1, on an enlarged scale;

FIGURE 6 is a sectional view, on an enlarged scale, taken substantiallyon line 66 of FIGURE 4, of the lower cam means and associated elements;

FIGURE 7 is a sectional view, on an enlarged scale, taken substantiallyon line 77 of FIGURE 4, of the lower cam means and associated parts; and

FIGURE 8 is a sectional view, on an enlarged scale, taken substantiallyon line 88 of FIGURE 4, of the lower cam means and associated elements,with the switch blades in contact closing'position.

It is assumed, for purposes of description, that the interrupter issuitably mounted in the position shown in "Ice FIGURE 1, though it maybe otherwise suitably disposed, as will be understood. The interrupterof my invention comprises an open frame having rectangular side plates10 and 11 spaced apart at one end by tubular posts 12 mounted on screwrods 13 passing through plate 11 and anchored in plate 10. The plates 10and 11 are spaced apart at their other end by an insulating block 14seating against the inner faces thereof and having lugs 15 fittingsnugly in corresponding openings in the plates. The block 14 is formedof a phenolic resin, or any suitable insulating material and the plates10 and 11 are held tightly seated against the sides of block 14 by screwrods 16 passing through plate 11 and threaded through plate 10 to whichthey are anchored in a suitable known manner. The frame and the partsmounted thereon are, in practice, enclosed by a transparent plastichousing, not shown, removably mounted on the frame by suitable means,conveniently securing screws.

A constant speed motor 20, preferably a synchronous motor of known type,is mounted on the outer face of plate 11. The drive shaft of motor 20extends through side plate 11 and has a spur pinion 21 secured on itsinner end. Pinion 21 meshes with a gear 22 fixed to one end of a gearand cam assembly 23 rotatably mounted on a cross rod 24 extendingbetween plates 10 and 11 with its ends anchored therein. The assembly 23is formed of a suitable plastic, preferably nylon, and comprises a cammember 25 having gear 22 at one end and a spur pinion 26 at its otherend. The cam member 25 is of a cross section to provide two lobes orrisers 27 of gradually increasing radius terminating in approximatelyradial shoulders 28 (FIGURE 5) respectively connected to the body of thecam by a short are 29 of a radius no greater than that of the associatedcam follower, to be referred to more fully presently.

The cam member 25 is rotated counter-clockwise, as viewed in FIGURE 5,and actuates three switch blades 31, 32 and 33 anchored at their outerends in block 14. The switch blades are formed of elongated strips ofberyllium copper, phosphor bronze, or other suitable metal, areresilient and possess appreciable rigidity or stiffness. They are formedat their inner ends to provide substantially U-shaped elements in whichcam followers, in the form of rollers 34 of small diameter, previouslymentioned, are rotatably mounted. The blades 31, 32 and 33 are sodisposed as to be flexed inward toward cam member 25 effective formaintaining the rollers.34 in pressure contact therewith. Each of theblades 31 and 33 is provided, on its outer face and a short distancefrom its inner end, with a contact element 35. The central switch blade32 is provided with two laterally projecting fingers 36 each having atits inner face a contact element 37. The contact elements 37 overliecontact elements 35 of blades 31 and 32 and the outer ends of the switchblades are connected to circuitry including the light or wink signalpreviously mentioned. The shoulders 28 of cam member 25 are spaced apartand the follower rollers 34 of switch blades 31 and 33 are spaced ashort distance in advance of the follower roller of switch blade 32,which is of correspondingly less effective length than blades 31 and 33.In the rotation of cam member 25, the shoulders 28 thereof pass beneaththe followers of blades 31 and 33, which then move along a shoulder 28radially inward of cam member 25, opening the contact elements 35 and36. Shortly thereafter, the cam shoulder passes beneath the follower ofswitch blade 32, which then moves radially inward, effective forabruptly closing the contact elements 35 and 36 and thereby closing thewinker light circuit. In the continued rotation of cam member 25, thecontact elements 35 and 36 remain closed until the second shoulder 28 ofthe cam member passes beneath the cam followers, thereby again brieflyopening the light circuit. Accordingly, the winker light circuit isbriefly interrupted at uniform time intervals of slight duration. Thecam member 25 in conjunction with the switch blades 31, 32 and 33 andassociated elements, constitutes the winker light section of theinterrupter of my invention.

The pinion 26 at the end of cam assembly 25 remote from gear 22 thereofmeshes with a gear 40, adjacent side plate 10, at one end of acompound'cam assembly 41 rotatably mounted on a cross rod 42 extendingbetween and anchored at its ends in side plates 10 and 11. ,The assembly41 may be formed of any suitable material, preferably nylon. Its innerend portion 41a, extending for approximately one half its length, is ofgenerally circular cross section and is provided with four equallyspaced arcuate lobes or ribs 43 (FIGURE 6) of equal radial extentprojecting radially outward therefrom and parallel with the axisthereof. The cam assembly 41 is further provided with an intermediateportion 41b (FIGURE 7) extending from the outer end of'portion 41a, andan outer end portion 41c (FIGURE 8) extending from portion 41b to gear40. The portions 41b and 410 are respectively of approximately one halfthe length of the inner end portion 41a. The portion 41b is of generallycircular cross section and, for the major portion of its circumference,is of a diameter approximately the same as that of portion 41a plus theheight or radial extent of two diametrically opposite ribs 43 of portion410, so that the circumferential surface of portion 41b, for the majorportion thereof, coincides with the crests of ribs 43. The portion 41bis provided with a circumferential recess extending the full lengththereof and of a depth such that the radius of portion 41b at suchrecess is approximately the same as that of portion 41a exclusive of theribs 43 thereof. The recess in portion 4111 provides the latter with twoshoulders 44 similar to those of the wink cam 25 and spaced apart adistance somewhat greater than that between two ribs 43 of portion 41aand of approximately the same height or radial extent as the latterribs. The portion 410 of cam assembly 41 is of circular cross sectionand of approximately the same diameter as portion 41a exclusive of theribs 43 thereof. It is provided with a lengthwise r-ib 45 ofsubstantially V-shape in cross section, parallel with the axis ofportion 410 and of a height or radial extent approximately the same asthe shoulders 44 of portion 41b. The rib 45 is spaced from the leadingone of the shoulders 44 approximately one third of the distancetherebetween.

The cam member 25 is rotated counter-clockwise, as viewed in FIGURE andat constant speed, thereby driving the cam assembly 41 clockwise, asviewed in FIGURES 6, 7 and 8, at a constant predetermined speed relativeto cam member-25. The lower cam assembly 41 cooperates with two sets ofswitch blades, comprising an upper set of blades 48 and a lower set ofblades 49 and 50. The upper set consists of five similar blades and thelower set consists of four substantially similar blades. The switchblades of the two sets are in the form of elongated strips of berylliumcopper, phosphor bronze, or any suitable metal and are anchored at theirouter ends in block 14. They are resilient and possess appreciablerigidity or stiffness. The blades 48 of the upper set are disposed abovea stop cross rod 51 formed of any suitable insulating material,preferably a phenolic resin. The rod 51 possesses substantial strengthand rigidity and extends between the side plates 10 and 11 with its endsfixed therein. Each of the blades 48 has a short finger 48a bentdownward at an obtuse angle and a short terminal portion or finger 48bbent reversely to finger 48aand extending in the same general direction,as the main or body portion of the blade. The blades 48 of the upperset are of equal length and terminate a short distance from the camassembly 41. The blades 50 of the lower set are similar and are parallelwith and underlie the three blades 48 of the upper set remote fromtheframe side plate 11., Blade 49 of the lower set underlies the upperblade 48 which is second from side plate 11 and is provided, a shortdistance from its inner end, with a laterally projecting finger 49awhich overlies finger 48b of upper blade 48 next adjacent side plate11.. The blades 49 and 50 of the lower set are of uniform length,somewhat greater than that of the blades 48 of the upper set. Each ofthe blades 49 and 50 is provided at its inner end with a substantiallyU-shaped member in which is rotatably mounted a roller cam follower 52.The rollers 52 are held, by the inherent resiliency ofblades 49 and 50in pressure contact with the corresponding portions of the cam assembly41.

The fingers 48b of the switch blades 48 have contact elements 55 securedon their lower faces. The lower switch blades 491and 50, and finger 49aof blade 49, have contact elements '56 secured to their upper faces inalignment with and opposed to contact elements 55. In the rotation ofthe cam assembly 41, when the follower rollers 52 are on the dwells ofthe respective portions of cam assembly 41, the contact elements 56 ofswitch blade 49 and finger 49a thereof and of the adjacent switch blade50, actuated by cam portion 41a, are held in pressure contact with thecontact, elements 55 of the three corresponding switch blades 48, thecontact element 56 of the switch blade 50 actuated by cam portion 41b isheld in open circuit position, spaced fromcontactielement -55 of thecorresponding blade 48, as in FIGURE 7, and the contact element 56 ofblade 50 actuated by cam portion 410 isin pressure contact with contactelement 55 of the corresponding blade 48, as in FIGURE 8. In thecontinued rotation of the cam assembly 41 the ribs 43 of portion 41amove the corresponding switch blades 49 and 50 outward, as in FIGURE 6,thereby opening the corresponding. circuits, the recess of portion 41bpermits inward movement of the corresponding switch blade 58 to closedcircuit position, and rib 45 of portion 41c moves the correspondingswitch blade 50 outward to open circuit position briefly and thenreleases it for return to normal closed circuit position. Fineadjustment of the spacing of the contact elements maybe made by slightbending of the blades, without necessity for adjustment thereof in theblock 14. In that manner, the supplementary circuits controlled by lowercam assembly 41 and associated elements are alternately closed'andopened in proper sequence and in predetermined relation to the openingand closing of the winker circuit above described.

In FIGURE 6, the blade 50 is shown in open circuit position, with thefollower 52 resting on a rib 43 of inner portion 41a of cam assembly 41.The blade 49 and its finger 49a are then also in open circuit position,as will be understood. In the continued rotation of cam assembly 41 theblades 49 and .50 are released and moved inward to closed circuitposition, due to their being under flexure, as aboveexplained. In likemanner, the other switch blades 50 are released and move inward toclosed circuit position. The pressure exerted by blade 49 flexes the twoupper blades 48 corresponding to blade 49 and finger 49a thereof, aslight distance away from the stop cross rod 51. Such flexing of theblades 48 results in a rubbing or sliding movement between the contactele ments 55 and 56 effective for maintaining them in a clean conditionassuring good contact therebetween under, all normal operatingconditions. That operation is shown more clearly in FIGURE 8, in whichblade 50 is shown in its closed circuit position.

When blade 49 or 50 is moved to open circuit position it is flexedoutwardly away from blades 48 effective for opening the contacts. Thestop rod 51 is so disposed that when the contacts are open the blades 48are flexed and under transverse tension, being then held by theirinherent resiliency in-pressure contact with rod 51 in close proximityto the angle between the bent portion 48a and the body portion of therespective blades. During outward movement of the blade 49 or 50, theblades 48, being under flexure move outward into contact with the stoprod 51, which eifectively restrains them against further outwardmovement. The blade 49 or 50 continues to move a slight distance furtheroutward after outward movement of blades 48 is stopped by rod 51, in thenormal opening of the contacts. In the event of incipient weldingtogether of the contact elements, the continued outward movement ofblade 49 or 50 is effective for breaking the weld and thereby assuringopening of such elements. In that connection, the angularly bent portion48a of the respective blades 48 is of importance. .The pull exerted inbreaking a Weld is transmitted substantially lengthwise of portion 48awhich is, in effect, anchored at its outer end to stop rod 51.Accordingly, the portion of the respective blades 48 extending inwardlybeyond rod 51 is not readily flexible and offers sufiicient resistanceto bending thereof to assure breaking of such welds as may occur.

Suitable known means, such as a circuit board 60, is provided forconnecting the switch blades in the proper circuitry, as will beunderstood. The particular means employed for that purpose is notessential to my present invention, and any suitable known means may beused, as will be understood.

It will be understood that changes in detail may be resorted to withoutdeparting from the field and scope of my invention, and I intend toinclude all such variations, as fall within the scope of the appendedclaims, in this application in which the preferred form only of myinvention has been disclosed.

Iclaim:

1. In a circuit interrupter, a cam, means for rotating said cam, a firstswitch blade having a cam follower and yieldingly urged toward said cameffectively holding said follower seated thereon, a second switch bladeterminating short of said cam and opposed to and yieldingly urged towardsaid first blade, opposed contact elements on said blades, said cambeing etfective for moving said first blade away from said second bladeand releasing said first blade for movement toward said second bladethereby opening and closing said contact elements, and stop meanscomprising a rigid, fixedly positioned member located in the path oftravel of the second blade to limit movement of said second blade towardsaid first blade to an extent less than the movement of said first bladein the opening of said contact elements.

2. In a circuit interrupter, a cam, means for rotating said cam, twoopposed resilient switch blades of generally elongated form anchored atone end and extending therefrom in substantially parallel overlyingrelation toward said cam, one of said blades having a cam follower heldby the inherent resiliency of said one blade seated on said cam and theother blade terminating short of said cam and being urged by itsinherent resiliency toward said one blade, said blades having opposedcontact elements spaced from said cam, the latter being elfective formoving said one blade away from said other blade and releasing said oneblade for movement toward said other blade thereby opening and closingsaid contact elements, and a rigid, fixedly positioned stop memberextending between said blades outward from said cam beyond said contactelements and disposed to limit movement of said other blade to an extentless than the movement of said one blade in the opening of said contactelements.

3. In a circuit interrupter, a cam, means for rotating said cam, twoopposed resilient switch blades of generally elongated form anchored atone end and extending therefrom in substantially parallel overlyingrelation toward said cam, one of said blades having a cam follower heldby the inherent resiliency of said one blade seated on said cam and theother blade terminating short of said cam and being urged by itsinherent resiliency toward said one blade, the tree end portion of saidother blade being bent to provide a first finger extending at an anglethereto toward said one blade and a second terminal finger extendingfrom said first finger substantially parallel to the body portion ofsaid other blade, said one blade and terminal finger of said other bladehaving opposed contact elements thereon, said cam being effective formoving said one blade away from said other blade and :for releasing saidone blade for movement toward said other blade thereby opening andclosing said contact elements, and a rigid, fixedly positioned stopmember extending between said blades in proximity to the angle betweensaid first finger and the body portion of said other blade and disposedto limit movement of said other blade to an extent less than themovement of said one blade in the opening of said contact elements.

4. In a circuit interrupter, a cam, means for rotating said earn, aplurality of resilient switch blades of generally elongated formanchored at one end and having at their other end cam followers heldseated on said cam by the inherent resiliency of said blades, a secondplurality of resilient switch blades of generally elongated form opposedto said first switch blades and urged by their inherent resiliencytoward the latter, said second blades terminating short of said cam andsaid first and second blades having opposed contact elements, said cambeing efiective for intermittently moving said first blades away fromsaid second blades and releasing said first blades for movement towardsaid second blades thereby opening and closing said opposed contactelements, and rigid, fixedly positioned stop mea-ns extending betweensaid blades effective for limiting movement of said second blades towardsaid first blades to an extent less than the movement of said firstblades in the opening of said contact elements.

5. In a circuit interrupter, a cam, means for rotating said cam, aplurality of resilient switch blades of generally elongated formanchored at one end and having at their other end cam followers heldseated on said cam by the inherent resiliency of said blades, a secondplurality of resilient switch blades of generally elongated form opposedto said first switch blades and urged by their inherent resiliencytoward the latter, said second blades terminating short of said cam andsaid first and second blades having opposed contact elements, said cambeing effective for intermittently moving said first blades away fromsaid second blades and releasing said first blades for movement towardsaid second blades thereby opening and closing said opposed contactelements, and an inflexible, nonyie'lding stop member extending betweensaid two sets of blades and disposed to limit movement of said secondblades toward said first blades to an extent less than the movement ofsaid first blades in the opening of said contact elements.

6. In a circuit interrupter, a frame comprising spaced side plates, acam between said plates, means for rotating said cam, a plurality ofresilient switch blades of generally elongated form anchored at one endto said frame and having at their other ends cam followers held seatedon said cam by the inherent resiliency of said blades, a secondplurality of resilient switch blades of generally elongated form opposedto said first switch blades and anchored at one end to said frame andurged by their inherent resiliency toward said first blades, said secondblades terminating short of said cam, the free end portions of saidsecond blades being respectively bent to provide a first fingerextending at an angle thereto toward a first blade and a second terminalfinger extending from said first finger substantially parallel to thebody portion of said second blade, said first blades and said secondfingers of said second blades havingopposed contact elements thereon,said cam being efieetive for moving said first blades away from saidsecond blades and for releasing said first blades for movement towardsaid second blades thereby opening and closing said contact elements,and an inflexible stop rod mounted in said side plates extending betweensaid two sets of blades in proximity to the angles between the bodyportions and said first fingers of said second blade and fixedlypositioned to limit movement of said second blades to an extent less 8than the movement of said first blades in the opening of said contactelements.

References Cited by the Examiner UNITED STATES PATENTS 2,317,967 4/1943Tuttle 200-6 X 2,644,062 6/1953 Wi'llia-ms 200-6 X ROBERT K. SCI-IAEFER,Primary Examiner.

1. IN A CIRCUIT INTERRUPTER, A CAM, MEANS FOR ROTATING SAID CAM, A FIRSTSWITCH BLADE HAVING A CAM FOLLOWER AND YIELDINGLY URGED TOWARD SAID CAMEFFECTIVELY HOLDING SAID FOLLOWER SEATED THEREON, A SECOND SWITCH BLADETERMINATING SHORT OF SAID CAM AND OPPOSED TO AND YIELDINGLY URGED TOWARDSAID FIRST BLADE, OPPOSED CONTACT ELEMENTS ON SAID BLADES, SAID CAMBEING EFFECTIVE FOR MOVING SAID FIRST BLADE AWAY FROM SAID SECOND BLADEAND RELEASING SAID FIRST BLADE FOR MOVEMENT TOWARD SAID SECOND BLADETHEREBY OPENING AND CLOSING SAID CONTACT ELEMENTS, AND STOP MEANSCOMPRISING A RIGID, FIXEDLY POSITIONED MEMBER LOCATED IN THE PATH OFTRAVEL OF THE SECOND BLADE TO LIMIT MOVEMENT OF SAID SECOND BLADE TOWARDSAID FIRST BLADE TO AN EXTENT LESS THAN THE MOVEMENT OF SAID FIRST BLADEIN THE OPENING OF SAID CONTACT ELEMENTS.